U.S. Pat. No. 4,127,098 discloses an arrangement wherein the legs of the spring, in the region of their guiding portions, extend parallel to each other over the entire length. The point of contact of the pawl pin is in the direction of rotation of the fan wheel behind a plane between the axis of rotation of the rotor and an axis of the pawl pin which defines a guide pin. After starting and during operation, the spring clip may thus rotate counterclockwise as a consequence of the occurring vibrations. This can cause the pawl to pivot radially outwardly and thereby engage the teeth of the fan wheel rotating at high speed. This causes wear of the pawl end and eventually shortens the pawl such that in the starting process it will pivot outwardly by a correspondingly larger angle which may result in breakage of the rotor or a failure of the pawl to engage with the teeth. As a result, the tool such as a chain saw or the like cannot be started.